1. Field of the Invention
The invention concerns with controlling computer program, controlling apparatus, and controlling method, in particular, controlling computer program, controlling apparatus, and controlling method for detecting infection by computer virus at the controlling apparatus.
2. Description of Related Art
Various technologies have been known for detecting infections by computer viruses (including worms), deleting or separating illegal programs and files caused by the computer viruses.
For example, Japanese Patent Application JP H09-171460A discloses a technology for detecting infections by computer viruses by means of comparing current program operations with operating specifications and/or typical operations under normal condition of a specific program, which are stored in advance. Japanese Patent Application JP H11-161517A discloses a technology for detecting infections by computer viruses based on changes in resources or file sizes stored in a apparatus such as a personal computer.
A technology has been developed in recent years that uses a personal computer loaded with a general purpose operating system as a controlling apparatus for controlling an image forming apparatus such as a Multi-Function Peripheral (MFP) instead of using hardware designed specifically for such an image forming apparatus. In such a case, the controlling apparatus that controls the image forming apparatus can get infected by computer viruses.
Many of the technologies of prior art, however, are designed to deal with infections by computer viruses of general purpose computers used for web page viewing, document preparations, e-mail transmissions, spreadsheet calculations, etc.
Many of the technologies of prior art detect computer viruses by finding signatures, format, and typical operations specific to the computer viruses in files by monitoring received or transmitted files. In such technologies, it is essential to store signatures, format, and typical operations specific to computer viruses as large scale database in order to detect the computer viruses. It is also necessary to update the database frequently to maintain it always current. Therefore, the work load for the preparation of the database is substantial. Also, it increases the load on CPU when detecting computer viruses as it makes it necessary to execute a large amount of comparison processes using a large database. Consequently, it can degrade the processing capability of the computer.
In case of a limited purpose apparatus, in particular, for example, a controlling apparatus for controlling an image forming apparatus, it may slow down the operation of the image forming apparatus due to an increase of the load on the CPU if anti-computer virus software for a general purpose computer is used.